A number representing the likelihood that a person will pay his or her debts. FICO stands for Fair Isaac Corporation, the company that developed the most widely used credit-scoring model. The three major U.S. consumer credit report agencies, Equifax, Experian, and TransUnion, collect data about consumers’ payment practices when paying on credit. The agencies then use the FICO modeling software to assess credit worthiness and derive a credit, or FICO, score.